Dr Chan told The New Paper: “Rats are one of the top five pests (in) enquiries monthly over the past two years.”

According to Dr Chan, all it takes are food, shelter and water for rats to find a home.

“Burrows are commonly dug by the pregnant rats where there is food and water available.

“One cm is all a rodent needs to enter a building. Old buildings without consistent or regular maintenance are most at risk of allowing entry points for rodents, through cracks, gaps and crevices,” he said.

In 2011, the NEA started an island-wide surveillance programme to monitor the rodent population.

Apart from detecting active rat burrows, potential causes of infestation like potential food sources are identified through this effort.

To further tackle this rat problem, a more coordinated approach among multiple stakeholders – including town councils and food shop operators – was piloted in Redhill Close, Bedok Central, Clementi Avenue 3 and Bangkit Road..

These stakeholders play their part through efforts like engaging their own pest control operators and coordinating their own rat control plans.

NEA has said that early results show a 15 to 70 per cent reduction in the number of burrows in each area.

From next month, NEA will also step up enforcement in Town Council areas.

In the meantime, the experts advise that food spills and waste be cleaned up.

Garbage bins covered and bulky items removed – so that the rodents don’t have places to hide and breed in.

Bite marks on goods and food packaging, gnaw marks on electrical cables and urine on walls are all signs that rats are around.

Said Dr Chan: “It is important to build awareness and education around storage and waste management like food waste and cleanliness as well as proper disposal of bulky items.”